Reuters –Tens of thousands of runners, including some of the world's best, and hundreds of thousands of fans are expected to hit the streets of Boston on Monday for the 119th running of the Boston Marathon.

Security will be high along the 26.2 mile course, in recognition of the bombing of the 2013 race, which killed three people and injured 264 in the one of the most visible attacks on U.S. soil since September11, 2001.

The race goes on during a pause in the trial of Dzhokhar Tsarnaev, the 21-year-old ethnic Chechen who was convicted earlier this month of the bombing. His trial will move into a second phase beginning on Tuesday, with prosecutors arguing that he should be sentenced to death for his crimes.

Police urged spectators not to bring large bags or coolers, saying that such packages would be subject to search. They also banned the use of drones along the course.

"We have significant resources and personnel out there to protect our public," said Mayor Martin Walsh. "It won't change our atmosphere. The city will be the same positive environment that people are used to enjoying during the Boston Marathon."

The field will include Meb Keflezighi of San Diego, who in 2014 became the first U.S. male to win the race in three decades, with a time of 2 hours, 8 minutes and 37 seconds, as well as top Kenya and Ethiopian contenders including Patrick Makau, Abel Kirui and Wilson Chebet.

The women's race will be wide open with three-time winner and reigning champion Rita Jeptoo of Kenya excluded from the race this year while she serves a two-year ban from the sport after failing a drug test.

Top women's contenders include Buzunesh Deba of Ethiopia, 2012 Boston winner Sharon Cherop of Kenya, as well as Shalane Flanagan, who originally hails from the Boston suburb of Marblehead, Massachusetts, who finished fourth in 2013.

In addition to attracting elite runners competing for the $830,500 in prize money, the world's oldest annual marathon is a mecca for dedicated amateurs who work for years to meet the strict, age-graded time cutoffs they must pass to earn a coveted spot in the field.

One group that will not be present at the race is the 12 jurors and six alternates in the Tsarnaev trial. U.S. District Judge George O'Toole ordered them to stay away from the race.